Cardiometabolic index has inverse nonlinear L-shaped associations with insulin resistance, prediabetes, and type 2 diabetes, with risk increasing up to a specific threshold before stabilizing, according to a recent study.
Researchers examined the associations between the cardiometabolic index (CMI) and insulin resistance (IR), prediabetes (preDM), and type 2 diabetes mellitus (T2D) in U.S. adults using data from 13,142 participants of the National Health and Nutrition Examination Survey from 2007 to 2020. CMI was calculated as the product of the triglyceride-to-high-density lipoprotein cholesterol ratio and the waist-to-height ratio.
The study, published in BMC Endocrine Disorder, demonstrated positive associations between CMI and markers of glucose metabolism, including fasting blood glucose, glycosylated hemoglobin, fasting serum insulin, and the homeostatic model assessment of insulin resistance. After adjusting for various confounding factors including age, gender, race, BMI, and other clinical and lifestyle variables, elevated CMI was associated with a higher likelihood of IR (odds ratio [OR], 3.51; 95% CI: 2.94-4.20), preDM (OR, 1.49; 95% CI: 1.29-1.71), and T2D (OR, 2.22; 95% CI: 2.00-2.47).
The analysis identified inverse nonlinear L-shaped associations between CMI and IR, preDM, and T2D, with inflection points at CMI values of 1.1, 1.45, and 1.6, respectively. Risk levels increased significantly until these thresholds, with odds ratios of 1.27 (95% CI: 1.25-1.29), 1.05 (95% CI: 1.04-1.07), and 1.12 (95% CI: 1.10-1.14) per 0.1 increase in CMI for IR, preDM, and T2D, respectively. Beyond these points, although the risks for IR, preDM, and T2D remained elevated, further increases in CMI did not significantly raise the risk, and the relationship began to level off.
The study also conducted subgroup analyses based on age, gender, race, and BMI, as well as sensitivity analyses excluding patients with preDM and T2D, which confirmed the robustness of the findings.
These findings suggest that lowering CMI below these thresholds could reduce the likelihood of developing IR, preDM, and T2D, while reductions beyond these points may offer limited additional benefit. The plateau effect suggests that maintaining CMI at certain levels is beneficial, but further reduction beyond these thresholds may not provide additional risk reduction.
Full disclosures can be found in the published study.